Phosphoinositide 3-kinases (PI3-Ks) catalyze the synthesis of the phosphatidylinositol (PI) second messengers PI(3)P, PI(3,4)P2, and PI(3,4,5)P3 (PIP3) (Fruman et al., 1998). In the appropriate cellular context, these three lipids control diverse physiological processes including cell growth, survival, differentiation and chemotaxis (Katso et al., 2001). The PI3-K family comprises 15 kinases with distinct substrate specificities, expression patterns, and modes of regulation (Katso et al., 2001). The class I PI3-Ks (p110α, p110β, p110δ, and p110γ) are activated by tyrosine kinases or G-protein coupled receptors to generate PIP3, which engages downstream effectors such as the Akt/PDK1 pathway, the Tec family kinases, and the Rho family GTPases. The class II and III PI3-Ks play a key role in intracellular trafficking through the synthesis of PI(3)P and PI(3,4)P2. The PIKKs are protein kinases that control cell growth (mTORC1) or monitor genomic integrity (ATM, ATR, DNA-PK, and hSmg-1).
The importance of these enzymes in diverse pathophysiology has made the PI3-K family the focus of intense interest as a new class of drug targets (Ward et al., 2003). This interest has been fueled by the recent discovery that p110α is frequently mutated in primary tumors (Samuels et al., 2004) and evidence that the lipid phosphatase PTEN, an inhibitor of PI3-K signaling, is a commonly inactivated tumor suppressor (Cantley and Neel, 1999). Efforts are underway to develop small molecule PI3-K inhibitors for the treatment of inflammation and autoimmune disease (p110δ, p110γ, and mTOR), thrombosis (p110β), viral infection (the PIKKs) and cancer (p110α, mTOR, and others). Recently, the first selective inhibitors of these enzymes have been reported (Camps et al., 2005; Condliffe et al., 2005; Jackson et al., 2005; Knight et al., 2004; Lau et al., 2005; Sadhu et al., 2003).
Protein tyrosine kinases, protein serine/threonine kinases, and lipid kinases are distinct classes of proteins that play critical roles in regulation and proliferation of cellular activity. Small molecules that inhibit these protein classes have the potential to disrupt dysfunctional/pathological pathways at two distinct points. For example, signaling through tyrosine kinase receptors is known to be disregulated in several types of cancer. This signaling pathway involves downstream proteins such as PI3 Kinase. Signaling through the serine/threonine protein kinase mTOR (also known as the mammalian target of rapamycin) is known to regulate cell growth, cell proliferation, cell motility, cell survival, protein synthesis, and transcription. Disruption of the mTOR pathway is implicated as a contributing factor to various human disease processes, especially various types of cancer. An inhibitor that blocks activity of protein tyrosine kinase and PI3 Kinase, mTOR and PI3Kinase, or mTOR, protein tyrosine kinase and PI3 Kinase, has the potential to stop the aberrant signaling at two or three different levels. Double or triple inhibition by a small molecule may magnify drug potency, increasing the compound's therapeutic potential.
The present invention meets these and other needs in the art by providing a new class of PI3 kinase antagonists, PI3 kinase and tryosine kinase antagonists, PI3Kinase and mTOR antagonists, and PI3Kinase, mTOR and tryosine kinase antagonists.